Polymorphonuclear leukocyte chemotaxis machinery (PMN chemotaxis machinery)

The polymorphonuclear leukocyte (PMN) chemotaxis machinery is a complex, multi-component system responsible for the directed migration of neutrophils toward sites of infection or injury [2, 8]. This machinery integrates signals from various cell-surface receptors, primarily G protein-coupled receptors (GPCRs) such as the formyl peptide receptor 1 (FPR1), C5a receptor (C5AR1), and chemokine receptors CXCR1 and CXCR2 [1, 3, 10]. Upon activation by chemoattractants like IL-8 or bacterial peptides, these receptors trigger intracellular signaling pathways involving phosphoinositide 3-kinase (PI3K), Rho GTPases, and tyrosine kinases [4, 8]. These pathways coordinate the rapid remodeling of the actin cytoskeleton and the microtubule network, allowing the cell to polarize and generate the mechanical force needed for locomotion [2, 7]. In clinical contexts, this machinery is a critical driver of inflammation; its overactivation contributes to tissue damage in conditions like acute respiratory distress syndrome (ARDS) and rheumatoid arthritis, while its impairment leads to recurrent infections [8, 10]. Therapeutic strategies targeting this machinery include the use of receptor antagonists, microtubule inhibitors like colchicine, and signaling inhibitors to modulate the intensity of the immune response [2, 4, 10].

Other names

Neutrophil chemotaxisLeukocyte recruitmentPMN migrationGranulocyte chemotaxisLeukocyte locomotion

Inhibition of microtubule polymerization (e.g., colchicine) [2], antagonism of chemokine receptors such as CXCR1 and CXCR2 (e.g., reparixin) [10], inhibition of tyrosine kinases (e.g., erbstatin) [4], and broad suppression of inflammatory mediator production (e.g., corticosteroids).